The present invention relates to various aspects of the lighting systems. In particular, the present invention relates lighting systems and illumination of partially or fully or enclosed spaces such as product display cases, grocery canopy, and under-shelf lighting in various display appliances.
The use of fluorescent lamps and lighting technology is well known in the lighting art. However, disadvantages of a fluorescent lamp and its ballast include the emission of heat as a side effect, which is counterproductive for use with a cooling apparatus. Further, unsafe conditions may occur in a fluorescent lighting system, including the possibility of high voltage arcing, which could either directly harm the installer, customers, or bystanders, or indirectly by starting a fire. The use of mercury in a fluorescent lamp poses a health hazard to store employees, customers or final consumers due to accidental breakage of a lamp allowing the mercury to contaminate the cabinet interior or product surfaces. Finally, fluorescent bulbs have a limited lifetime, requiring inconvenient replacement.
Attempts have been made in the art to replace the less reliable and higher voltage fluorescent bulbs with more reliable and energy efficient solid state lighting such as light emitting devices. The use of solid state lighting has various advantages; however, some of the disadvantages include the need for separate power supply/power converter units that incur loss of energy and generation of undesired heat. Further, solid state lighting include localized lighting devices that do not provide uniform lighting over a wide area.
Often theater lighting uses multiple localized light sources to adjust illumination to highlight individuals or produce other scenic effects. Differences and size and scale notwithstanding, the result differs from the needs for uniform display of a product or uniform lighting of a personnel compartment.
Accordingly, there remains a need for an improved illumination system and technology for more uniform or controlled gradient illumination of substantially enclosed spaces.